diff -up utfcpp-3.1/CMakeLists.txt.gtest utfcpp-3.1/CMakeLists.txt
--- utfcpp-3.1/CMakeLists.txt.gtest	2019-04-26 23:49:17.000000000 +0200
+++ utfcpp-3.1/CMakeLists.txt	2019-10-22 09:44:02.721256016 +0200
@@ -32,6 +32,5 @@ endif()
 
 if(UTF8_TESTS)
     enable_testing()
-    add_subdirectory(extern/gtest)
     add_subdirectory(tests)
 endif()
diff -up utfcpp-3.1/tests/CMakeLists.txt.gtest utfcpp-3.1/tests/CMakeLists.txt
--- utfcpp-3.1/tests/CMakeLists.txt.gtest	2019-04-26 23:49:17.000000000 +0200
+++ utfcpp-3.1/tests/CMakeLists.txt	2019-10-22 09:46:24.165698530 +0200
@@ -16,15 +16,18 @@ target_link_libraries(negative PRIVATE u
 target_link_libraries(cpp11 PRIVATE
     utf8::cpp
     gtest_main
+    gtest
     )
 target_link_libraries(apitests PRIVATE
     utf8::cpp
     gtest_main
+    gtest
 )
 
 target_link_libraries(noexceptionstests PRIVATE
     utf8::cpp
     gtest_main
+    gtest
 )
 target_compile_options(noexceptionstests PUBLIC -fno-exceptions)